Symphony of Sin
by ImagineBagginsDragon
Summary: Deanmon is on the loose, and will raise a little hell. Evil!Demon Dean.


_**Author's Note: I wrote this on Wattpad as well, but the administrators blocked it at school. Thus, here it is, probably different. I will finish it on here, but it isn't finished on Wattpad.**  
_

* * *

Chuck frantically looked for his booze to ease the vision he knew was coming on, but it was too late. He felt it tear at his skull and he hoped he had enough liquor in his system to help dull the intense pain. His eyesight blurred, then cleared.

* * *

 _Dean was seated on the arm of a musty old couch, which creaked occasionally in protest. His shirt was tight, and he carelessly held a mostly full beer bottle by the neck between two fingers._

 _His jeans rode low on his hips, advertising, his tanned lowermost abs and uppermost thighs._

 _His eyes were pools of endless, seething oily black. His face wore a smirk that rarely ceased to exist, and he looked like the embodiment of temptation._

 _Castiel didn't often feel the need to swallow, but his mouth felt dry._

 _A motel sign flickered in the background, letters glowing red while a devil with a three-pronged trident moved back and forth periodically._

 _Dean licked his lips, took a long drink from the beer bottle, and turned his gaze to the angel. "So, Cassie, I know that at the moment I have you trapped, but bear with me."_

 _He leaned forward, bracing his upper body with an elbow that rested on the adjacent knee. His eyes transitioned quickly back to normal a moment to glance at the holy flames licking the air._

 _"Word on the street is that if you commit the greatest sin, you instantly become the king of Hell, no questions asked. However, there's been debate and experimentation. What is the greatest sin?" He appeared thoughtful, but it was exaggerated and sarcastic._

 _"I would like to know your thoughts on the matter," he continued, staring at Castiel. He took another drink from his beer._

 _Castiel remained stoically silent, face illuminated by the flames._

 _Dean knew damn well how provocative he looked, and hooked a thumb into the waistband of his jeans._

 _"Tsk, tsk. Avoiding polite conversation? What would Daddy think about your faux pas?" His words held more venom than a rattlesnake._

 _The angel's jaw clenched at Dean's words, and his eyes glittered. The demon was thrilled that he riled Cas up, but it wasn't enough._

 _He wanted to know what the greatest sin to commit was, and if Castiel didn't relent, then he'd have to get creative._

 _"Will you be a good boy if I let you out?" asked Dean mockingly. He stood, prowling outside the circle._

 _Castiel didn't react, except to utter quiet, desperate instinctual noises._

 _"Answer me or you'll rot for eternity in there!" Dean roared, smashing the bottle against the floor._

 _"I will be civil," Castiel finally replied. Dean grinned, grabbing a jug of water that could be hefted with only one hand.  
_

 _With reflexes quick as lightning and senses heightened to the point that he could discern a fly tapping against the faulty lightfixtures in the hall, he doused a large portion of the fire and his arm shot out to grab Castiel's.  
_

 _The angel wasn't fast enough._

 _"Oh no, Angelface-" Dean purred, as the angel tried to fly away to no avail, "-you're going nowhere."_

 _He slapped a metal wristband engraved with an angel-binding sigil onto Cas's wrist._

 _The demon cupped the angel's cheek, stroking his face with a thumb. "Want to know what I think is the greatest sin?" Dean asked, tracing his thumb over Castiel's lips._

 _Castiel placed his hands on Dean's chest, but didn't push him away._

 _Dean got closer, and they could feel each other's hot breath caressing their necks. Cas's hands snaked up Dean's shirt, ghosting over his abs._

 _Their breaths hitched, and Dean's lips quirked upward in amusement. "Almost there, sweetheart."_

 _He brought his other hand up, and brought Castiel's inexperienced, plush lips to his own._

 _The angel was floundering and confused, but he relaxed into it and Dean stopped making irate noises at the awkward teeth grinding._

 _Castiel, with Dean's guidance, leaned into it more and they grew impatient, and frenzied._

 _The demon shoved Cas against the wall, yanking at his pristine white shirt. Buttons flew and the shirt fell to the floor in rags._

 _Dean growled ferally, eyes changing to jet-black once more. They wouldn't return to normal again._

 _He turned Castiel around, and tugged off the trench coat that the angel so loved. It made a pitiful puddle of tan on the floor._

 _Castiel was left in a blue tie and pants, and Dean threw him onto the bed._

 _Dust billowed from the old furniture, but it bothered neither of them. Castiel sat up, looking for all the world like a disciple awaiting judgement, and Dean tore his shirt from his body.  
_

 _Chuck didn't want to see anymore; though it hadn't worked often, he struggled to be freed from the nightmarish vision._

 _Dean slowly ambled forward and gave Castiel access to the front of his jeans, and the angel began to fumble with the button and zipper frantically._

 _"No! No! I don't want to see anymore!" he cried out, thrashing his ethereal form._

 _"Chuck!" A voice came from seemingly nowhere._

* * *

"Chuck!" The voice tore him from the vision, and Chuck bolted upright.

He blinked twice at the man before him. "Sam?"

Sam towered over him, worry plastered across his face. "You were having a vision, right? You were screaming. What did you see?"

Chuck shivered. "Oh, God." He stood, and lumbered across the room. "Did you see my whiskey anywhere?"

Sam frowned. "That bad?" Chuck nodded, and triumphantly held aloft a large bottle of the dark liquid and brandished it towards Sam. "Open it, will you?"

Sam took it and broke the seal, and handed it back to the prophet. "Thank you," Chuck sighed, taking a long swig, adam's apple bobbing in his throat as he took in a lot of liquor.

"Okay, I think-" he hiccuped, "-that I'm good. In my vision, Dean was there, and he had Castiel in an angel trap. He mentioned something about wanting to commit the 'greatest sin'."

Sam took a seat. "The greatest sin? They know for sure what it is?"

Chuck shook his head and took another long drink. "Every demon, according to Dean, is trying everything possible to figure it out. Dean, I think, tried to commit it, and he might find it, or at least get damn close."

Sam stared at Chuck, and he continued.

"He freed Cas, but then he put some kind of angel-trapping sigil wristband on him. Then, they were going to..." he paused to look at Sam apologetically, "do the horizontal nasty. You woke me up before I saw it (thank you so much) but it seemed inevitable."

Sam's eyes widened in disbelief. "What!?"

Chuck grinned feebly and took another swig of alcohol. "You heard me right. I don't know what to make of it."

Sam's hand went to his forehead as he stood to pace.

 _That sounds like it pretty much is the greatest sin. If Castiel had consensual sex with a knight of Hell, and a guy, so he'd be intentionally depurifying himself, but does that mean that he committed the greatest sin, or that Dean did? _Sam thought.

"Did he say why they want to commit sins?" Sam asked, swiveling to face the prophet.

"He said it made them insta-king of Hell. Crowley would be demoted. Not far, but still demoted nonetheless. I gotta tell you; if Dean ruled Hell, he'd probably sacrifice demons for fun. Demonocide. While that's awesome and all, we might never be able to get him to come back from Hell. I hate to even think it, Sam, but if there's anything left of Dean inside, it's dying. He's a demon through and through."

Sam growled. "Why didn't you say that? He may not be actively trying to be king of Hell, but this sin might just get him there. And if you're right about him never being able to come back, we have to stop it from coming true."

Chuck saluted Sam with his bottle. "Better go fast. The vision takes place tomorrow at around ten o'clock at night. They'll be at the El Diablo Motel in Minnesota."


End file.
